Navien
Navien Adaptor S.H Return 30025803A
System hot return adaptor for Navien NCB500 combi boilers, part number 30025803A.
£44.21
£36.84 ex. VAT · VAT at 20%
Same-day dispatch
Ordered by 4pm Mon–Fri, 10:30am Sat.
30-day returns
Unused, in original packaging.
What it is
The Navien adaptor S.H return (part number 30025803A) is a system hot return connection component used on Navien NCB500 combi boilers. It forms the return-side pipework connection on the appliance, allowing the heating circuit return to be coupled to the boiler. It is supplied as a single service part for the NCB500 combi range.
Signs this part needs replacing
- Weeping or dripping at the system return connection
- Visible corrosion, staining or scale on the adaptor body or threads
- Loss of system pressure traced to the return pipework at the boiler
- Reduced flow or uneven heating linked to a restricted return connection
- Damaged threads or a marked sealing face after servicing
Before you order
- Confirm the boiler model matches one of the NCB500 variants listed above
- Check the appliance serial number against the manufacturer's parts list
- Compare the existing adaptor and its connection against the part before ordering
- Isolate and drain the boiler before removal
No specification data held for this part.
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| NAVIEN NCB500-1S+/32K COMBI - (Serial Number 3924) | — | — | — | |
| NAVIEN NCB500-1S+/32K COMBI - (Serial Number 3924) | — | — | — | |
| NAVIEN NCB500-2S+/41K COMBI - (Serial Number 3712) | — | — | — | |
| NAVIEN NCB500-2S+/41K COMBI - (Serial Number 3712) | — | — | — | |
| NAVIEN NCB500-2S/37K COMBI - (Serial Number 3735) | — | — | — | |
| NAVIEN NCB500-2S/37K COMBI - (Serial Number 3735) | — | — | — |
Documents & drawings
Everything we hold for this part. Where a document exists but we don't hold it, the technical team will source it from the manufacturer — usually the same working day.
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